Texas Retina’s Ashkan M. Abbey, MD, recently co-authored an article in the medical journal Eye on the use of a novel deep-learning algorithm to quantify retinal fluid changes in patients treated with faricimab for neovascular (wet) age-related macular degeneration (AMD) through the TRUCKEE study.

Called the Notal OCT Analyzer (NOA) algorithm, this new measurement approach provided researchers with intraretinal, subretinal and total retinal fluid counts for each optical coherence tomography (OCT) scan conducted on the 521 eyes included in their review.

Reducing Retinal Fluid Accumulation to Help Prevent Vision Loss
With wet AMD, abnormal blood vessels grow under the retina and may leak, causing accumulation of blood or other fluid. This can cause permanent vision loss.

Wet AMD treatments aim to reduce the number of abnormal blood vessels and fluid accumulation. Retina specialists use OCT scans to measure change in retinal thickness or central subfield thickness (CST) as an indicator of retinal fluid levels. This helps them to manage treatment of the disease.

About the TRUCKEE Study
A collaborative study across multiple sites in the U.S., the TRUCKEE study is evaluating faricimab (Vabysmo), a monoclonal antibody delivered via intravitreal injection to treat adults with neovascular (wet) AMD. Approved by the U.S. Food and Drug Administration (FDA) in January 2022, faricimab targets two pathways of neovascular AMD: vascular endothelial growth factor A (VEGF-A) and angiopoetin-2 (Ang-2). Both promote abnormal growth and leakage of blood vessels in the eye.

“Faricimab is intended to provide more durability than other anti-VEGF injections, so patients can extend the amount of time between their injections,” explains Dr. Abbey. “This helps to reduce the treatment burden.”

Employing New Technology to Measure Treatment Effectiveness
In the recently published article, Dr. Abbey and his colleagues shared some of the limitations of solely using change in CST measured through an OCT scan as the basis for determining the amount of fluid present in the retina:

  • Smaller amounts of fluid may be obscured by the measurement variance of much larger thickness values.
  • Thickness changes can occur for reasons other than fluid presence, such as diffuse retinal thickness or subretinal fibrosis.
  • The same volume of fluid can cause different amounts of thickness changes depending on the distribution of fluid volume pockets in the retina.
  • Retinal thickness change value alone does not characterize if the change was due to intraretinal or subretinal fluid, or potentially a combination of both.

“These limitations led to our interest in developing algorithms that more directly quantify the retinal fluid volume demonstrated in OCT images,” says Dr. Abbey. “This is accomplished in part by segmenting fluid pixels present in the intraretinal and subretinal spaces. The additional and more precise information we gain helps us to more accurately measure retinal fluid accumulation and treatment effectiveness.”

Measured using the new deep-learning algorithm, key findings reported in this latest study included the following:

  • Of all 521 eyes, 49.9% demonstrated fluid reduction after one injection of faricimab.
  • The mean fluid reduction after one injection was −60.7nL.
  • The proportion of eyes that saw reduction in fluid compared to baseline after second, third, fourth and fifth faricimab injections were 54.4%, 51.9%, 51.4% and 52.2%, respectively.

“In our previous research, faricimab had demonstrated efficacy in visual acuity and anatomy with comparable safety and increased durability,” reports Dr. Abbey. “Through this latest real-world sub-analysis utilizing the deep learning algorithm, we were able to quantify retinal fluid resolution to demonstrate improvement at a more precise level. While we continue to study the durability and safety of faricimab, we’re excited about what we’ve seen so far and the positive impacts it is having on our patients.”

Click here to access the full article or here to learn about all the clinical trials currently available at Texas Retina.

About Dr. Abbey
Dr. Abbey serves as Texas Retina’s Director of Clinical Research for Dallas and cares for patients in our Dallas Main and Rockwall offices. You can learn more about him here.